scholarly journals The interaction between AMPKβ2 and the PP1-targeting subunit R6 is dynamically regulated by intracellular glycogen content

2016 ◽  
Vol 473 (7) ◽  
pp. 937-947 ◽  
Author(s):  
Yvonne Oligschlaeger ◽  
Marie Miglianico ◽  
Vivian Dahlmans ◽  
Carla Rubio-Villena ◽  
Dipanjan Chanda ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Glycogen Content ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type

Breakdown of intracellular glycogen enhances interaction of the AMPKβ2 subunit and the R6 glycogen-targeting subunit of protein phosphatase type 1 (PP1), which occurs in conjunction with increased β2-Thr-148 phosphorylation.

Induction of hepatic glycogenesis in the fetal rat

1989 ◽  
Vol 256 (1) ◽  
pp. E49-E54 ◽  
Author(s):  
P. A. Gruppuso ◽  
D. L. Brautigan
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatase ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Hepatic Glycogen ◽  
Phosphatase Activities ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type

We have performed an in vivo study to test the hypothesis that induction of fetal hepatic glycogenesis is stimulated by insulin and involves activation of protein phosphatase type-1. Control animals and the following two experimental groups were studied: maternal fasting for 48 h prior to term and chronic maternal hyperinsulinemia for 5 days prior to term. Maternal fasting led to decreased fetal hepatic glycogen content and fetal growth retardation. In contrast, no decrease in fetal hepatic glycogen content or fetal weight occurred with maternal hyperinsulinemia despite fetal hypoglycemia and fetal hypoinsulinemia. In neither model were fetal hepatic synthase phosphatase or phosphorylase phosphatase activities affected. In control fetuses, the appearance of hepatic glycogen from days 17 to 21 of gestation correlated with induction of glycogen synthase. Phosphorylase phosphatase and synthase phosphatase activities already were present on day 17 of gestation and changed little through term. However, phosphatase catalytic protein reactive with anti-phosphatase type-1 antibodies did increase approximately fivefold from day 18 to 21. In adult animals fasted for 48 h, 50% of hepatic glycogen synthase phosphatase activity was lost, whereas phosphorylase phosphatase activity was stimulated fourfold. The apparent size of protein phosphatase type-1 catalytic subunit as detected by Western immunoblotting was altered by fasting in the adult but not by substrate restriction (maternal fasting) in the fetus.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Ectopic Expression of Inhibitors of Protein Phosphatase Type 1 (PP1) Can Be Used to Analyze Roles of PP1 in Drosophila Development

Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 235-245
Author(s):  
Daimark Bennett ◽  
Balázs Szöőr ◽  
Sascha Gross ◽  
Natalia Vereshchagina ◽  
Luke Alphey
Keyword(s):  
Protein Phosphatase ◽  
Muscle Development ◽  
Ectopic Expression ◽  
High Specificity ◽  
Type I ◽  
Protein Phosphatase Type 1 ◽  
Mitotic Figures ◽  
Protein Phosphatase Type

Abstract We have identified two proteins that bind with high specificity to type 1 serine/threonine protein phosphatase (PP1) and have exploited their inhibitory properties to develop an efficient and flexible strategy for conditional inactivation of PP1 in vivo. We show that modest overexpression of Drosophila homologs of I-2 and NIPP1 (I-2Dm and NIPP1Dm) reduces the level of PP1 activity and phenotypically resembles known PP1 mutants. These phenotypes, which include lethality, abnormal mitotic figures, and defects in muscle development, are suppressed by coexpression of PP1, indicating that the effect is due specifically to loss of PP1 activity. Reactivation of I-2Dm:PP1c complexes suggests that inhibition of PP1 activity in vivo does not result in a compensating increase in synthesis of active PP1. PP1 mutants enhance the wing overgrowth phenotype caused by ectopic expression of the type II TGFβ superfamily signaling receptor Punt. Using I-2Dm, which has a less severe effect than NIPP1Dm, we show that lowering the level of PP1 activity specifically in cells overexpressing Punt is sufficient for wing overgrowth and that the interaction between PP1 and Punt requires the type I receptor Thick-veins (Tkv) but is not strongly sensitive to the level of the ligand, Decapentaplegic (Dpp), nor to that of the other type I receptors. This is consistent with a role for PP1 in antagonizing Punt by preventing phosphorylation of Tkv. These studies demonstrate that inhibitors of PP1 can be used in a tissue- and developmental-specific manner to examine the developmental roles of PP1.

Differential expression of protein phosphatase type 1 isotypes and nucleolin during cell cycle arrest

2007 ◽  
Vol 25 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Hiroyuki Morimoto ◽  
Akiko Ozaki ◽  
Hirohiko Okamura ◽  
Kaya Yoshida ◽  
Bruna Rabelo Amorim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Differential Expression ◽  
Protein Phosphatase ◽  
Cycle Arrest ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type

Phosphorylation of the Protein Phosphatase Type 1 Inhibitor Protein CPI-17 by Protein Kinase C

2007 ◽  
pp. 209-224 ◽  
Author(s):  
Michael P. Walsh ◽  
Marija Susnjar ◽  
Jingti Deng ◽  
Cindy Sutherland ◽  
Eniko Kiss ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Inhibitor Protein ◽  
Kinase C ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type

scholarly journals Ypi1, a Positive Regulator of Nuclear Protein Phosphatase Type 1 Activity in Saccharomyces cerevisiae

2008 ◽  
Vol 19 (3) ◽  
pp. 1032-1045 ◽  
Author(s):  
Jennifer P. Bharucha ◽  
Jennifer R. Larson ◽  
Lu Gao ◽  
Lisa K. Daves ◽  
Kelly Tatchell
Keyword(s):  
Protein Phosphatase ◽  
Nuclear Protein ◽  
Spindle Checkpoint ◽  
Regulatory Subunit ◽  
Aurora B ◽  
Binding Partner ◽  
Protein Phosphatase Type 1 ◽  
Positive Regulators ◽  
Protein Phosphatase Type

The catalytic subunit of protein phosphatase type 1 (PP1) has an essential role in mitosis, acting in opposition to the Ipl1/Aurora B protein kinase to ensure proper kinetochore-microtubule interactions. However, the regulatory subunit(s) that completes the PP1 holoenzyme that functions in this capacity is not known. We show here that the budding yeast Ypi1 protein is a nuclear protein that functions with PP1 (Glc7) in this mitotic role. Depletion of cellular Ypi1 induces mitotic arrest due to activation of the spindle checkpoint. Ypi1 depletion is accompanied by a reduction of nuclear PP1 and by loss of nuclear Sds22, a Glc7 binding partner that is found in a ternary complex with Ypi1 and Glc7. Expression of a Ypi1 variant that binds weakly to PP1 also activates the spindle checkpoint and suppresses the temperature sensitivity of an ipl1-2 mutant. These results, together with genetic interactions among YPI1, GLC7, and SDS22 mutants, indicate that Ypi1 and Sds22 are positive regulators of the nuclear Glc7 activity that is required for mitosis.

scholarly journals Binding of select forms of pRB to protein phosphatase type 1 independent of catalytic activity

Oncogene ◽  
1999 ◽  
Vol 18 (54) ◽  
pp. 7803-7809 ◽  
Author(s):  
Sama Tamrakar ◽  
Sibylle Mittnacht ◽  
John W Ludlow
Keyword(s):  
Catalytic Activity ◽  
Protein Phosphatase ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type
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